On the Production of W–Fe–B Ternary Compounds by Self-propagating High-Temperature Synthesis

In this study, one-step production of W₂FeB₂ and WFeB compounds from oxide raw materials was carried out through cost-effective and energy-efficient aluminothermic self-propagating high-temperature synthesis (SHS). Accordingly, the feasibility of SHS in the production of W₂FeB₂ and WFeB compounds was discussed. In addition, the selected SHS products of W₂FeB₂ were re-melted through arc melting to investigate the structure modification of W₂FeB₂ phase at high temperature. Prior to experimental work, raw material amounts, adiabatic temperatures, and phase diagram were calculated by FactSage™ software. The phase, microstructure, and compositional analyses were performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), respectively. The formation of γ-Fe, FeB and orthorhombic W₂FeB₂ phases was detected for the samples that were mainly composed of WFeB, while W₂FeB₂-rich samples contained α-WB. Moreover, XRD analysis results suggested the formation of a trace amount of ternary W₃FeB₃ phase in the W₂FeB₂-rich samples. High-temperature structure modification of W₂FeB₂ (tetragonal) with arc melting was also successfully conducted. Vickers hardness test results were found to be in the range of 1007 to 2157 HV and WFeB containing samples possessed lower hardness than W₂FeB₂-rich samples. The experimental results revealed that SHS could be an alternative and promising feasible synthesis route for the production of W₂FeB₂/WFeB ternary borides.